玄武岩钛同位素分析标准物质研制

The preparation of reference material for titanium isotope measurement of basalt

同位素标准物质是进行同位素准确分析的基础和关键,其同位素组成是同位素测量的基本参数。本文报道了玄武岩钛同位素标准物质的研制过程和定值结果,包括标准物质的选择、均匀性和稳定性检验、定值分析及测定数据的统计性检验等。玄武岩钛同位素标准物质的主要特性量值的推荐值及95%置信水平的不确定度为:δ^(47)Ti(‰)=-0.53±0.07,δ^(48)Ti(‰)=-1.05±0.09,δ^(49)Ti(‰)=-1.57±0.16,δ^(50)Ti(‰)=-2.10±0.18。该标准物质可用于地质样品钛同位素测定中化学流程评价和验证、质谱仪的校正及整个过程的分析质量控制。

Isotopic reference materials are crucial to isotopic measurement, and isotopic compositions of reference materials constitute basic parameters for isotopic measurement. This paper deals with the new reference material with basaltic matrix for Ti isotope measurement. The preparation of the reference material strictly followed the relevant metroiogical technical standard stipulated by the state, which included homogeneity and stability tests and certification analyses. The certified values and uncertainty at the 95 % confidence level were δ47Ti（‰） = -0.53±0.07, δ48Ti（‰）=-1.05±0.09, δ49Ti（‰）= -1.57±0.16 and δ50Ti（‰）= -2.10±0.18. This newly certified reference material can be used for assessment of isotope fractionation during chemical separation of geological samples instrumental calibration in Ti isotope measurements, and data quality evaluation in the whole process of sample preparation and isotope measurement.